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Suggested LAS 1.5 Time Offset Values

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Evon Silvia edited this page Sep 7, 2023 · 1 revision

>>>>> DRAFT <<<<<

LAS 1.5 allows users of the LAS format to specify a time offset other than 1 billion, which was and is the offset value used by Adjusted Standard GPS Time in LAS versions 1.1 through 1.4.

In order to maximize compatibility between datasets covering similar time periods, the LWG recommends using standardized values incrementing by 250 million. This increment optimizes GPS Time precision to approximately 100 nanoseconds for a given 8 year period.

  1. 500M = 1991-2000
  2. 750M = 1999-2008
  3. 1000M = 2007-2015 <--- current Adjusted Std GPS Time Offset
  4. 1250M = 2015-2023
  5. 1500M = 2023-2031
  6. 1750M = 2031-2039
  7. 2000M = 2039-2047

Note that the Time Offset value is encoded as an unsigned 16-bit integer, and each increment of the Time Offset is equal to 1 million seconds.

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